Neonatal Outcomes of Mothers With a Disability

We performed a population-based cohort study in Ontario. Ontario is the largest province in Canada, with a population of 14.7 million residents and 140 000 births per year.²¹  Ontario has a universal health care system, wherein all primary and acute care, including care of mothers and newborns, is delivered at no direct cost. We accessed and analyzed linked health administrative datasets at ICES (Toronto, Ontario), an independent, nonprofit organization that holds medical and sociodemographic data derived from Ontario residents’ health care encounters. We used the MOMBABY dataset, derived from hospital discharge abstracts, to identify maternal-newborn records for all hospital births, which represent >98% of births in Ontario.²¹  We also used ICES data to identify all hospitalizations, emergency department visits, outpatient physician visits, immigration status, and other sociodemographic characteristics (Table 1). Datasets were linked using a unique encoded identifier. ICES datasets are accurate and complete for primary hospital diagnoses, recorded using International Classification of Diseases and Related Health Problems 10^th revision or Diagnostic and Statistical Manual of Mental Disorders fourth edition codes; outpatient physician diagnoses, recorded using billing claims codes; and sociodemographic data.²²  The use of data for this study was authorized under section 45 of Ontario’s Personal Health Information Protection Act, which does not require review by a Research Ethics Board.

We identified all singleton livebirths that were conceived between April 1, 2003 and March 31, 2018 to 15- to 49-year-old women. Maternal disability status was determined using definitions of physical, sensory, and intellectual or developmental disabilities developed from published algorithms for measuring disability in health administrative data.^23–25  Details have been reported previously.²⁶  Briefly, maternal physical (ie, congenital anomaly, musculoskeletal disorder, neurologic disorder, or permanent injury), sensory (ie, hearing or vision loss), intellectual or developmental (ie, autism spectrum disorder, chromosomal or autosomal anomalies resulting in intellectual disability, or developmental disability such as fetal alcohol spectrum disorder), and multiple disabilities (diagnoses in ≥2 of these categories) were defined as being present if a relevant diagnostic code was recorded in ≥2 physician visits or ≥1 emergency department visits or hospitalizations between database inception and the pregnancy’s conception date. The estimated date of conception was back-calculated from the index birth date minus the gestational weeks at birth.²⁷  Women without any recognized disability were the comparator.

Outcomes were indicators of birth timing, growth, and neonatal morbidity and mortality defined by the Canadian Perinatal Surveillance System,²⁸  namely, preterm birth at <37 and <34 weeks’ gestation; small for gestational age (birth weight <10th percentile for gestational age)²⁹ ; large for gestational age (>90^th percentile)²⁹ ; neonatal morbidity (brachial plexus injury or palsy, convulsions of the newborn, grade III or IV intraventricular hemorrhage or periventricular leukomalacia, hypoxic ischemic encephalopathy, neonatal sepsis, persistent fetal circulation or neonatal hypertension, or respiratory distress syndrome) <28 days; neonatal abstinence syndrome; NICU admission; and neonatal mortality at <28 days.

Using Misra et al’s integrated perinatal health framework,³⁰  we measured factors related to the social determinants of health, preconception health, and health care access that reflect disparities between women with and without disabilities.^11–17  Maternal age and parity were derived from the MOMBABY dataset. Neighborhood income quintile was measured by linking residential postal codes with Census area-level income data. Rural residence was measured using the Rurality Index of Ontario, which is based on community characteristics such as travel time to referral centers.³¹  Immigrant or refugee status was determined from the Immigrants, Refugees, and Citizenship Canada Permanent Residents Database. Chronic medical conditions were measured using the Johns Hopkins Adjusted Clinical Groups (ACG) System v. 10 collapsed ambulatory diagnostic groups, which classifies nondisability conditions as stable or unstable based on acute health care patterns.³²  Mental illness (ie, psychotic, mood or anxiety, or other disorders) and substance use disorders were ascertained based on ≥2 physician visits or ≥1 emergency department visits or hospital admissions less than 2 years before conception. The Revised Graduated Prenatal Care Utilization Index³³  measured prenatal care adequacy based on the timing of initiation of care and number of visits and served as an indicator of health care access. In a subsample of births in 2007 to 2018 with data linkable to a clinical birth registry (the Better Outcomes Registry and Network), we measured smoking in pregnancy. Finally, we measured pregnancy complications (ie, gestational diabetes, gestational hypertension, preeclampsia and eclampsia, venous thromboembolism, or severe maternal morbidity)³⁴  and delivery mode.

We used frequencies and percentages to describe women with physical, sensory, intellectual or developmental, and multiple disabilities and computed standardized differences to compare them to women without disabilities.³⁵ 

We employed modified Poisson regression³⁶  to directly estimate a relative risk (RR) and 95% confidence interval (CI) for each neonatal outcome, comparing each disability group to women without disabilities. We used generalized estimating equations to account for inclusion of multiple newborns born to the same mother during the study period.³⁷  We derived minimally adjusted models including maternal age, parity, neighborhood income quintile, rural residence, and immigrant status, and models including these variables and further adjusting for stable and unstable chronic conditions, mental illness, substance use disorders, and prenatal care adequacy.

We carried out several additional analyses. In a subsample of births in 2007 to 2018, we further adjusted models for maternal smoking. Since pregnancy and delivery complications may also affect neonatal outcomes, and are more common in women with disabilities,¹⁰  we also stratified models according to (1) the presence of pregnancy complications and (2) delivery mode. Finally, we examined neonatal outcomes according to disability subtype.

All analyses used SAS version 9.4.

From 2003 to 2018, there were 144 187 newborns delivered to women with a physical disability, 44 988 to women with a sensory disability, 2207 to women with an intellectual or developmental disability, 8823 to women with multiple disabilities, and 1 593 354 to women without any recognized disability. Compared with women without disabilities, women with intellectual or developmental disabilities were younger and more likely to live in neighborhoods in the lowest income quintile. Women with physical and multiple disabilities were more likely to have stable chronic conditions, and those with physical, intellectual or developmental, and multiple disabilities were more likely to have unstable chronic conditions. All 4 disability groups were more likely to have mental illness and to smoke, and women with intellectual or developmental and multiple disabilities were more likely to have substance use disorders (Table 2).

With few exceptions, newborns of women with disabilities, compared with those of women without disabilities, had higher rates of preterm birth at <37 weeks (7.3%–9.9% across disability groups, versus 6.2% in newborns of women without disabilities), preterm birth at <34 weeks (1.8%–2.6%, versus 1.5%), small for gestational age (11.7%–17.0%, versus. 12.3%), and large for gestational age (7.7%–9.6%, versus 8.1%). In the fully adjusted models, newborns of women with disabilities remained more likely to be born preterm at <37 and <34 weeks’ gestation. All disability groups, except newborns of women with physical disabilities, were more likely to be small for gestational age, and all, except newborns of women with intellectual or developmental disabilities, were more likely to be large for gestational age. For all outcomes, newborns of women with intellectual or developmental and multiple disabilities had the highest risks (adjusted risk ratios ranging from 1.37–1.53, and 1.09–1.58, respectively) (Table 3).

Likewise, newborns of women with disabilities, compared with those of women without disabilities, had higher rates of neonatal morbidity (8.9%–12.1%, versus 7.7%), neonatal abstinence syndrome (0.62%–2.7%, versus 0.48%), NICU admission (13.2%–20.6%, versus 11.7%), and neonatal mortality (0.22%–0.29%, versus 0.19%). In fully adjusted models, all disability groups remained at increased risk for neonatal morbidity, and all, except newborns of women with sensory disabilities, were at increased risk for neonatal abstinence syndrome. All disability groups were at increased risk for NICU admission. Risks for neonatal mortality were elevated but were nonsignificant, likely because of the small numbers for this rare but serious outcome. Again, for all outcomes, newborns of women with intellectual or developmental and multiple disabilities had the highest risks (adjusted risk ratios 1.27–1.53, and 1.28–1.87, respectively) (Table 4).

In additional analyses, risks were slightly reduced when further adjusting for maternal smoking (Supplemental Tables 5 and 6). Some risks were attenuated among mothers who experienced pregnancy complications (Supplemental Tables 7 and 8); findings were largely consistent whether newborns were delivered by caesarean or vaginal delivery (Supplemental Tables 9 and 10). Risks were elevated across all specific disability subtypes (Supplemental Tables 11 and 12).

In this large, population-based study, we found that newborns of women with disabilities were at increased risk for a range of relatively rare neonatal complications. Elevations in risk were mild to moderate across all disability groups compared with women without a disability and were highest for newborns of women with intellectual or developmental and multiple disabilities. Risks largely remained elevated after adjustment, after stratification by the presence of delivery mode, and, to a lesser extent, pregnancy complications, and in analyses by specific subtype of disability. These findings demonstrate that, to support the best possible outcomes for all newborns, women with disabilities may benefit from enhanced preconception and prenatal care, followed by family-centered supports after birth, that are tailored to their unique needs.

A growing number of studies, mostly from the United States, have examined neonatal outcomes in women with disabilities.²⁰  A recent meta-analysis of these studies showed higher risk of preterm birth in newborns of women with sensory (pooled unadjusted odds ratio [pOR] 1.37, 95% CI 1.27–1.48; 7 studies) and intellectual or developmental disabilities (pOR 1.76, 95% CI 1.59–1.96; 12 studies), compared with newborns of women without disabilities.²⁰  There was also elevated risk of low birth weight in newborns of women with physical (pOR 1.81, 95% CI 1.47–2.23; 3 studies), sensory (pOR 1.36, 95% CI 1.18–1.57; 4 studies), and intellectual or developmental disabilities (pOR 1.98, 95% CI 1.50–2.61; 5 studies).²⁰  However, most of these studies were rated as having low or moderate quality, with lack of control for confounding being the most common limitation. Moreover, few studies examined other important newborn outcomes, such as neonatal morbidity and mortality.²⁰  Therefore, the current study adds to the literature by examining risks of a broad range of neonatal outcomes, overall and after adjusting for preexisting maternal disparities related to the social determinants of health, preconception health, and prenatal care adequacy, and after stratifying by pregnancy and delivery-related factors.

It is understood that women with disabilities are disproportionately impacted by socioeconomic disparities, physical and mental health conditions, and health behaviors, such as smoking,^11–17,38  and often have difficulty accessing prenatal care.^18,19  They are also at elevated risk for pregnancy complications and caesarean delivery.^10,26  In the general population, these factors are known predictors of neonatal complications.^39,40  Observed risks of adverse outcomes in newborns of women with disabilities were partly, but not completely, explained by adjustment for prepregnancy social and health disparities and smoking in pregnancy, and stratification by pregnancy complications and caesarean delivery. This finding is an important indicator of the multifaceted nature of the observed risks, given that women with disabilities experience many known risk factors for neonatal complications.^11–17,38  Other unmeasured factors could also partly explain our results. At the provider and system level, women with disabilities encounter barriers to timely, coordinated, and high-quality care, including physically inaccessible care environments; communication that does not address sensory or cognitive needs; inadequate provider knowledge about disability; negative provider attitudes about disability, pregnancy, and parenting; and fragmentation of health and social services.^41–43  At the individual level, factors such as medication use⁴⁴  could also contribute to risks for specific outcomes such as preterm birth, small for gestational age, and neonatal abstinence syndrome; however, medication use could not be measured. Future studies should examine how these factors contribute to neonatal complications in this population to improve understanding of risk attributable to modifiable provider and system-level and individual-level risk factors, and to generate targets for support.

Although most neonatal complications are rare, our findings have important implications for clinical practice. Many of the outcomes we examined, including preterm birth and small for gestational age, are preventable through better access to preconception and prenatal care.^45,46  Our data suggest women with disabilities could benefit from improved access to high-quality health care before and during pregnancy that is adapted to their needs. Although women with disabilities in our cohort had similar rates of prenatal care access as those without disabilities, we had no indicators of the quality or appropriateness of that care. However, prior research has shown gaps in these areas.^41–43  Given high rates of chronic disease, mental illness, and smoking among these women,^14–17  prenatal care should emphasize chronic condition management and health promotion using accessible approaches that meet the needs of women with disabilities. Higher rates of preterm birth, neonatal morbidity, and NICU admission in newborns of women with disabilities show a need to consider the physical, communication, and other disability accommodation needs of mothers with a newborn in the NICU, as well as additional practical and emotional supports for mothers in the immediate newborn period. Post discharge, family-centered approaches to newborn care should consider barriers new mothers with disabilities may encounter, including physical inaccessibility of physician offices; hearing, vision, or cognitive-related communication barriers; cognitive difficulties related to memory and organizational skills; as well as difficulties navigating other community supports such as breastfeeding clinics.^41,42  Since obstetric supports for women in Canada drop off after 6 weeks postpartum, such family-centered approaches are critical for new mothers with disabilities who are at risk for postpartum complications themselves.^47,48  Finally, the structural barriers experienced by women with disabilities^18,19  make it imperative for clinicians to address the social determinants of health, including poverty. All of these efforts will require robust training and resources for obstetricians, pediatricians, and other health care providers to understand the unique needs of women with disabilities.

Study strengths include the use of a large, population-based cohort, and the ability to adjust for factors related to the social determinants of health, preconception health, smoking, and health care access that prior studies have not considered.²⁰  Several limitations must be noted. We used diagnoses to measure disability; this approach reflects a medical model of disability, and does not consider functional limitations or how the environment influences women’s lived experience of disability.⁴⁹  This approach, although well-established in prior research,^9,17,23–26  likely conservatively biased the findings in that some women who had disabilities may not have been accurately classified—for example, if their disability was undiagnosed, or their diagnosis was not recorded. The disability groups examined represent diverse populations whose experiences may differ. Consistent with prior research,²⁶  we conducted analyses by disability subtype, and showed findings were largely consistent in newborns of women with different disabilities within larger categories used in our main analyses. However, some heterogeneity in outcomes could exist at an even more granular level of specific disability diagnosis. We examined several outcomes, thus increasing the risk of type 1 error. However, the focus of our discussion is on the magnitude of the effects rather than their statistical significance. Unmeasured confounding may partly explain our results. For example, we had no individual-level data on socioeconomic status, nor did we have data on race and ethnicity.⁵⁰  The dual impact of experiences of ableism and racism on neonatal outcomes is an important are for future research. We also had no information on pathway variables that might explain the relation between maternal disability and neonatal complications, including medication use.⁴⁴  Further, our measures of prenatal care timing and number of visits could not assess care quality, including negative provider attitudes, lack of provider knowledge, and other factors that might impact quality.^18,19  We also could not measure additional supports women might have received outside the health care system because of their disability. Despite these limitations, this is one of the largest and most comprehensive analyses of neonatal outcomes in women with disabilities to date.²⁰ 

This population-based cohort study found a mild to moderate elevated risk of complications in newborns of women with disabilities, with the highest risks observed in those with an intellectual or developmental disability, or with multiple disabilities. Whereas most of the observed outcomes are rare, the findings indicate a need for improved health care to prevent them. Women with disabilities may benefit from customized preconception and prenatal care, followed by tailored, family-centered supports after birth to reduce their risks. Birth outcomes and the neonatal period are important predictors of lifelong health and development,^5,6  indicating improved preconception, prenatal, and neonatal care are critical for this under-served population.

Parts of this material are based on data and/or information compiled and provided by the Canadian Institute for Health Information (CIHI) and Immigration, Refugees and Citizenship Canada (IRCC) current to March 31, 2018. However, the analyses, conclusions, opinions and 358 statements expressed in the material are those of the author(s), and not necessarily those of CIHI or IRCC. This Study is based in part on data provided by Better Outcomes Registry and Network (“BORN”), part of the Children’s Hospital of Eastern Ontario. The interpretation and conclusions contained herein do not necessarily represent those of BORN Ontario.

CI

confidence interval

pOR

pooled unadjusted odds ratio

RR

relative risk